A Collection is an Object that has items
or orderedItems
however, orderedItems
is valid on both Collection and OrderedCollection! it is defined like this in the as2 context:
"orderedItems": {
"@id": "as:items",
"@type": "@id",
"@container": "@list"
}
so it is basically just an alias for items
where it MUST be an array, and the array’s order matters. (if it were @container: set
, then it MUST be an array, but the array’s order does not matter.)
tangent: a Collection may be ordered without being an OrderedCollection [link]
OrderedCollection is defined as strictly reverse chronological by ActivityPub. however, other orderings are valid on regular Collections. the use of the orderedItems
term allows plain-JSON implementations to do exactly this.